// Copyright (c) 2017 Baidu, Inc.
// 
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// 
//     http://www.apache.org/licenses/LICENSE-2.0
// 
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

// Intentionally no header guard


// Authors: Zhangyi Chen (chenzhangyi01@baidu.com)

namespace brpc {

struct HeaderCstr {
    const char* name;
    const char* value;
};

static const HeaderCstr s_static_headers[] = {
    {":authority", ""},
    {":method", "GET"},
    {":method", "POST"},
    {":path", "/"},
    {":path", "/index.html"},
    {":scheme", "http"},
    {":scheme", "https"},
    {":status", "200"},
    {":status", "204"},
    {":status", "206"},
    {":status", "304"},
    {":status", "400"},
    {":status", "404"},
    {":status", "500"},
    {"accept-charset", ""},
    {"accept-encoding", "gzip, deflate"},
    {"accept-language", ""},
    {"accept-ranges", ""},
    {"accept", ""},
    {"access-control-allow-origin", ""},
    {"age", ""},
    {"allow", ""},
    {"authorization", ""},
    {"cache-control", ""},
    {"content-disposition", ""},
    {"content-encoding", ""},
    {"content-language", ""},
    {"content-length", ""},
    {"content-location", ""},
    {"content-range", ""},
    {"content-type", ""},
    {"cookie", ""},
    {"date", ""},
    {"etag", ""},
    {"expect", ""},
    {"expires", ""},
    {"from", ""},
    {"host", ""},
    {"if-match", ""},
    {"if-modified-since", ""},
    {"if-none-match", ""},
    {"if-range", ""},
    {"if-unmodified-since", ""},
    {"last-modified", ""},
    {"link", ""},
    {"location", ""},
    {"max-forwards", ""},
    {"proxy-authenticate", ""},
    {"proxy-authorization", ""},
    {"range", ""},
    {"referer", ""},
    {"refresh", ""},
    {"retry-after", ""},
    {"server", ""},
    {"set-cookie", ""},
    {"strict-transport-security", ""},
    {"transfer-encoding", ""},
    {"user-agent", ""},
    {"vary", ""},
    {"via", ""},
    {"www-authenticate", ""}
};

BAIDU_CASSERT(ARRAY_SIZE(s_static_headers) == 61u,
              number_of_entries_in_static_table_must_be_61);

struct HuffmanCode {
    uint32_t code;
    uint32_t bit_len;
};

static const HuffmanCode s_huffman_table[] = {
    {0x1ff8, 13},
    {0x7fffd8, 23},
    {0xfffffe2, 28},
    {0xfffffe3, 28},
    {0xfffffe4, 28},
    {0xfffffe5, 28},
    {0xfffffe6, 28},
    {0xfffffe7, 28},
    {0xfffffe8, 28},
    {0xffffea, 24},
    {0x3ffffffc, 30},
    {0xfffffe9, 28},
    {0xfffffea, 28},
    {0x3ffffffd, 30},
    {0xfffffeb, 28},
    {0xfffffec, 28},
    {0xfffffed, 28},
    {0xfffffee, 28},
    {0xfffffef, 28},
    {0xffffff0, 28},
    {0xffffff1, 28},
    {0xffffff2, 28},
    {0x3ffffffe, 30},
    {0xffffff3, 28},
    {0xffffff4, 28},
    {0xffffff5, 28},
    {0xffffff6, 28},
    {0xffffff7, 28},
    {0xffffff8, 28},
    {0xffffff9, 28},
    {0xffffffa, 28},
    {0xffffffb, 28},
    {0x14, 6},
    {0x3f8, 10},
    {0x3f9, 10},
    {0xffa, 12},
    {0x1ff9, 13},
    {0x15, 6},
    {0xf8, 8},
    {0x7fa, 11},
    {0x3fa, 10},
    {0x3fb, 10},
    {0xf9, 8},
    {0x7fb, 11},
    {0xfa, 8},
    {0x16, 6},
    {0x17, 6},
    {0x18, 6},
    {0x0, 5},
    {0x1, 5},
    {0x2, 5},
    {0x19, 6},
    {0x1a, 6},
    {0x1b, 6},
    {0x1c, 6},
    {0x1d, 6},
    {0x1e, 6},
    {0x1f, 6},
    {0x5c, 7},
    {0xfb, 8},
    {0x7ffc, 15},
    {0x20, 6},
    {0xffb, 12},
    {0x3fc, 10},
    {0x1ffa, 13},
    {0x21, 6},
    {0x5d, 7},
    {0x5e, 7},
    {0x5f, 7},
    {0x60, 7},
    {0x61, 7},
    {0x62, 7},
    {0x63, 7},
    {0x64, 7},
    {0x65, 7},
    {0x66, 7},
    {0x67, 7},
    {0x68, 7},
    {0x69, 7},
    {0x6a, 7},
    {0x6b, 7},
    {0x6c, 7},
    {0x6d, 7},
    {0x6e, 7},
    {0x6f, 7},
    {0x70, 7},
    {0x71, 7},
    {0x72, 7},
    {0xfc, 8},
    {0x73, 7},
    {0xfd, 8},
    {0x1ffb, 13},
    {0x7fff0, 19},
    {0x1ffc, 13},
    {0x3ffc, 14},
    {0x22, 6},
    {0x7ffd, 15},
    {0x3, 5},
    {0x23, 6},
    {0x4, 5},
    {0x24, 6},
    {0x5, 5},
    {0x25, 6},
    {0x26, 6},
    {0x27, 6},
    {0x6, 5},
    {0x74, 7},
    {0x75, 7},
    {0x28, 6},
    {0x29, 6},
    {0x2a, 6},
    {0x7, 5},
    {0x2b, 6},
    {0x76, 7},
    {0x2c, 6},
    {0x8, 5},
    {0x9, 5},
    {0x2d, 6},
    {0x77, 7},
    {0x78, 7},
    {0x79, 7},
    {0x7a, 7},
    {0x7b, 7},
    {0x7ffe, 15},
    {0x7fc, 11},
    {0x3ffd, 14},
    {0x1ffd, 13},
    {0xffffffc, 28},
    {0xfffe6, 20},
    {0x3fffd2, 22},
    {0xfffe7, 20},
    {0xfffe8, 20},
    {0x3fffd3, 22},
    {0x3fffd4, 22},
    {0x3fffd5, 22},
    {0x7fffd9, 23},
    {0x3fffd6, 22},
    {0x7fffda, 23},
    {0x7fffdb, 23},
    {0x7fffdc, 23},
    {0x7fffdd, 23},
    {0x7fffde, 23},
    {0xffffeb, 24},
    {0x7fffdf, 23},
    {0xffffec, 24},
    {0xffffed, 24},
    {0x3fffd7, 22},
    {0x7fffe0, 23},
    {0xffffee, 24},
    {0x7fffe1, 23},
    {0x7fffe2, 23},
    {0x7fffe3, 23},
    {0x7fffe4, 23},
    {0x1fffdc, 21},
    {0x3fffd8, 22},
    {0x7fffe5, 23},
    {0x3fffd9, 22},
    {0x7fffe6, 23},
    {0x7fffe7, 23},
    {0xffffef, 24},
    {0x3fffda, 22},
    {0x1fffdd, 21},
    {0xfffe9, 20},
    {0x3fffdb, 22},
    {0x3fffdc, 22},
    {0x7fffe8, 23},
    {0x7fffe9, 23},
    {0x1fffde, 21},
    {0x7fffea, 23},
    {0x3fffdd, 22},
    {0x3fffde, 22},
    {0xfffff0, 24},
    {0x1fffdf, 21},
    {0x3fffdf, 22},
    {0x7fffeb, 23},
    {0x7fffec, 23},
    {0x1fffe0, 21},
    {0x1fffe1, 21},
    {0x3fffe0, 22},
    {0x1fffe2, 21},
    {0x7fffed, 23},
    {0x3fffe1, 22},
    {0x7fffee, 23},
    {0x7fffef, 23},
    {0xfffea, 20},
    {0x3fffe2, 22},
    {0x3fffe3, 22},
    {0x3fffe4, 22},
    {0x7ffff0, 23},
    {0x3fffe5, 22},
    {0x3fffe6, 22},
    {0x7ffff1, 23},
    {0x3ffffe0, 26},
    {0x3ffffe1, 26},
    {0xfffeb, 20},
    {0x7fff1, 19},
    {0x3fffe7, 22},
    {0x7ffff2, 23},
    {0x3fffe8, 22},
    {0x1ffffec, 25},
    {0x3ffffe2, 26},
    {0x3ffffe3, 26},
    {0x3ffffe4, 26},
    {0x7ffffde, 27},
    {0x7ffffdf, 27},
    {0x3ffffe5, 26},
    {0xfffff1, 24},
    {0x1ffffed, 25},
    {0x7fff2, 19},
    {0x1fffe3, 21},
    {0x3ffffe6, 26},
    {0x7ffffe0, 27},
    {0x7ffffe1, 27},
    {0x3ffffe7, 26},
    {0x7ffffe2, 27},
    {0xfffff2, 24},
    {0x1fffe4, 21},
    {0x1fffe5, 21},
    {0x3ffffe8, 26},
    {0x3ffffe9, 26},
    {0xffffffd, 28},
    {0x7ffffe3, 27},
    {0x7ffffe4, 27},
    {0x7ffffe5, 27},
    {0xfffec, 20},
    {0xfffff3, 24},
    {0xfffed, 20},
    {0x1fffe6, 21},
    {0x3fffe9, 22},
    {0x1fffe7, 21},
    {0x1fffe8, 21},
    {0x7ffff3, 23},
    {0x3fffea, 22},
    {0x3fffeb, 22},
    {0x1ffffee, 25},
    {0x1ffffef, 25},
    {0xfffff4, 24},
    {0xfffff5, 24},
    {0x3ffffea, 26},
    {0x7ffff4, 23},
    {0x3ffffeb, 26},
    {0x7ffffe6, 27},
    {0x3ffffec, 26},
    {0x3ffffed, 26},
    {0x7ffffe7, 27},
    {0x7ffffe8, 27},
    {0x7ffffe9, 27},
    {0x7ffffea, 27},
    {0x7ffffeb, 27},
    {0xffffffe, 28},
    {0x7ffffec, 27},
    {0x7ffffed, 27},
    {0x7ffffee, 27},
    {0x7ffffef, 27},
    {0x7fffff0, 27},
    {0x3ffffee, 26},
    {0x3fffffff, 30},
};

BAIDU_CASSERT(ARRAY_SIZE(s_huffman_table) == 257u,
              sizeof_s_huffman_table_must_be_257);

const static int32_t HPACK_HUFFMAN_EOS = 256;

} // namespace brpc
